The present invention relates to a device for determining the properties of surfaces.
The optical impression of objects or their surfaces, in particular the surfaces of motor vehicles, is decisively determined by their surface properties. Since the capability of the human eye to objectively evaluate surface properties is limited, there is a need of auxiliaries and equipment for qualitatively and quantitatively determining the properties of surfaces.
The properties of surfaces determined are for example gloss, orange peel, color, macro- and/or micro texture, distinctness of image, haze, surface texture and/or topography, and the like.
Devices are known from the prior art in which a radiation means projects radiation onto the examined measuring surface and the radiation reflected and/or diffused off said measuring surface is captured and evaluated by a detector. Many applications require or prefer that an examination of the reflected radiation includes the color or the individual spectral components.
To this end the prior art has used filters positioned in the optical path between the radiation means and the radiation detector. On the other hand it is also preferred in the prior art to measure under different angles the radiation reflected off the measured surface. In this case a plurality of detectors is applied.
For this reason the prior art places several filter means in the individual optical paths between the radiation means and various radiation detectors. It is known to provide one or more filters in every optical path.
On the one hand this will raise the costs for such devices since a large number of filters must always be installed. On the other hand these configurations may also reduce precision since although specified for the same wavelengths filters do not always accurately comprise identical optical properties such that equal filters may still lead to unequal measured results.